Renable -Wimplicit-fallthrough for PDFium.

Didn't find any bugs, but also doesn't require much boilerplate.

Bug: TODO
Change-Id: I5f30183c55216f1333c79fcb46476d281720873e
Reviewed-on: https://pdfium-review.googlesource.com/26210
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>

4 files changed, 10 insertions, 0 deletions

diff --git a/core/fpdfapi/page/cpdf_allstates.cpp b/core/fpdfapi/page/cpdf_allstates.cpp
index afc87a2b5a..d2491bbee7 100644
--- a/core/fpdfapi/page/cpdf_allstates.cpp
+++ b/core/fpdfapi/page/cpdf_allstates.cpp
@@ -12,6 +12,7 @@
 #include "core/fpdfapi/page/cpdf_streamcontentparser.h"
 #include "core/fpdfapi/parser/cpdf_array.h"
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fxcrt/fx_fallthrough.h"
 #include "core/fxge/cfx_graphstatedata.h"
 #include "third_party/base/stl_util.h"
 
@@ -89,6 +90,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         if (pGS->KeyExist("TR2")) {
           continue;
         }
+        FX_FALLTHROUGH;
       case FXBSTR_ID('T', 'R', '2', 0):
         m_GeneralState.SetTR(pObject && !pObject->IsName() ? pObject : nullptr);
         break;
@@ -131,6 +133,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         if (pGS->KeyExist("BG2")) {
           continue;
         }
+        FX_FALLTHROUGH;
       case FXBSTR_ID('B', 'G', '2', 0):
         m_GeneralState.SetBG(pObject);
         break;
@@ -138,6 +141,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         if (pGS->KeyExist("UCR2")) {
           continue;
         }
+        FX_FALLTHROUGH;
       case FXBSTR_ID('U', 'C', 'R', '2'):
         m_GeneralState.SetUCR(pObject);
         break;
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index af80fd96ab..e871e0a578 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -26,6 +26,7 @@
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fxcrt/cfx_memorystream.h"
 #include "core/fxcrt/fx_extension.h"
+#include "core/fxcrt/fx_fallthrough.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/numerics/safe_conversions.h"
 #include "third_party/base/ptr_util.h"
@@ -133,6 +134,7 @@ bool CPDF_DataAvail::CheckDocStatus() {
       return LoadAllFile();
     case PDF_DATAAVAIL_PAGE_LATERLOAD:
       m_docStatus = PDF_DATAAVAIL_PAGE;
+      FX_FALLTHROUGH;
     default:
       m_bDocAvail = true;
       return true;
diff --git a/core/fpdfapi/render/cpdf_dibtransferfunc.cpp b/core/fpdfapi/render/cpdf_dibtransferfunc.cpp
index 3b0e8b25a9..959fec383d 100644
--- a/core/fpdfapi/render/cpdf_dibtransferfunc.cpp
+++ b/core/fpdfapi/render/cpdf_dibtransferfunc.cpp
@@ -10,6 +10,7 @@
 
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/render/cpdf_transferfunc.h"
+#include "core/fxcrt/fx_fallthrough.h"
 
 CPDF_DIBTransferFunc::CPDF_DIBTransferFunc(
     const RetainPtr<CPDF_TransferFunc>& pTransferFunc)
@@ -119,6 +120,7 @@ void CPDF_DIBTransferFunc::TranslateScanline(
     }
     case FXDIB_Rgb32:
       bSkip = true;
+      FX_FALLTHROUGH;
     case FXDIB_Argb: {
       int index = 0;
       for (int i = 0; i < m_Width; i++) {
diff --git a/core/fpdfapi/render/cpdf_renderstatus.cpp b/core/fpdfapi/render/cpdf_renderstatus.cpp
index 66688a2d4c..6525164547 100644
--- a/core/fpdfapi/render/cpdf_renderstatus.cpp
+++ b/core/fpdfapi/render/cpdf_renderstatus.cpp
@@ -49,6 +49,7 @@
 #include "core/fpdfdoc/cpdf_occontext.h"
 #include "core/fxcrt/autorestorer.h"
 #include "core/fxcrt/cfx_fixedbufgrow.h"
+#include "core/fxcrt/fx_fallthrough.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "core/fxcrt/maybe_owned.h"
 #include "core/fxge/cfx_defaultrenderdevice.h"
@@ -1765,6 +1766,7 @@ bool CPDF_RenderStatus::ProcessText(CPDF_TextObject* textobj,
         // Already handled above, but the compiler is not smart enough to
         // realize it. Fall through.
         NOTREACHED();
+        FX_FALLTHROUGH;
       case TextRenderingMode::MODE_CLIP:
         return true;
     }